Nanoscale-Patterned Cr Films by Selective Etching Using a Heat-Mode Resist: Implications for X-ray Beam Splitter

Nanoscale-patterned chromium (Cr) metal structures are widely used in a large variety of semiconductor processing fields. These structures are usually fabricated via the direct etching method. Owing to the drawbacks of traditional lithography techniques (such as electron beam, ion beam, and scanning probe lithography), it is still a high-cost and complex work to accomplish nanoscale structure fabrication. In this paper, through laser heat-mode lithography, a chalcogenide AgInSbTe (AIST) film is chosen as the dry-etching resist to fabricate a series of arbitrary micro/nanostructures on the Cr film. The etching mechanism from the AIST resist to the Cr mask under the Cl-2/O-2-based gases has been elucidated through energy-dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. A grating pattern with a minimum pitch of 300 nm has been achieved on the Cr mask, and successfully transferred onto a diamond substrate as an X-ray beam splitter. This work provides an effective method for nanoscale structure fabrication and clarifies the antietching mechanisms of AIST resist films under Cl-based plasma etching.